Materiały źródłowe

• #1

  https://journals.lww.com/10.1097/BOR.0000000000001076

  This review aims to synthesize recent developments in the epidemiology of idiopathic inflammatory myopathies (IIMs), focusing on incidence, prevalence, disease classification, and clinical outcomes. […] IIM is a rare group of autoimmune diseases characterized by muscle weakness and systemic involvement, with incidence rates ranging from 0.2 to 2 cases per 100 000 person-years. […] Continued epidemiological research is essential to elucidate underlying mechanisms and inform future interventions, ultimately aiming to enhance the quality of life and clinical outcomes for affected patients.

• #2 Incidence and prevalence of idiopathic inflammatory myopathies in Thailand from the Ministry of Public Health data analysis | Scientific Reports

  https://www.nature.com/articles/s41598-024-71633-7

  The epidemiology of idiopathic inflammatory myopathies (IIMs) varies by country. […] We aimed to assess the prevalence and incidence of IIM in the Thai population between 2017 and 2020. […] The prevalence and incidence of IIMs were analyzed with their 95% confidence intervals (CIs) and then categorized by sex and region. […] In 2017, the IIM cases numbered 9,074 among 65,204,797 Thais, resulting in a prevalence of 13.9 per 100,000 population (95% CI 13.6-14.2). […] Between 2018 and 2020, the incidence of IIMs slightly declined from 5.09 (95% CI 4.9-5.27) in 2017 and 4.92 (95% CI 4.7-5.10) in 2019 to 4.43 (95% CI 4.2-4.60) per 100,000 person-years in 2020. […] The majority of cases occurred in southern Thailand, with incidence rates of 7.60, 8.34, and 8.74 per 100,000 person-years.

• #3

  https://consultqd.clevelandclinic.org/case-study-muscle-weakness-does-not-always-mean-myositis

  IIM, also known as myositis, is a heterogeneous group of autoimmune disorders that can be classified into multiple subgroups: dermatomyositis, polymyositis, anti-synthetase syndrome, immune-mediated necrotizing myopathy and overlap myositis. These conditions are relatively rare, with an incidence of 0.2-2 per 100,000 person-years and an annual prevalence of 2-25 per 100,000 individuals. […] Laboratory tests usually show a significant elevation in CK levels (often 1,000 U/L) and the presence of myositis-specific antibodies in 50% to 60% of cases. […] This case highlights the importance of differentiating between these conditions and IIM to avoid unnecessarily exposing patients without IIM to systemic immunosuppressive treatments. Obtaining and performing a comprehensive medical history, physical examination, laboratory/serologic workup, electromyography, muscle biopsy and genetic testing are often critical to avoid an incorrect diagnosis. […] Certain clinical features that are incongruent with IIM and might point to an alternative diagnosis include slow evolution of weakness over years, family history of muscle weakness, asymmetrical weakness and predominantly distal muscle weakness.

• #4

  https://journals.lww.com/10.1097/BOR.0000000000001076

  This review aims to synthesize recent developments in the epidemiology of idiopathic inflammatory myopathies (IIMs), focusing on incidence, prevalence, disease classification, and clinical outcomes. […] IIM is a rare group of autoimmune diseases characterized by muscle weakness and systemic involvement, with incidence rates ranging from 0.2 to 2 cases per 100 000 person-years. […] Continued epidemiological research is essential to elucidate underlying mechanisms and inform future interventions, ultimately aiming to enhance the quality of life and clinical outcomes for affected patients.

• #5 Epidemiology of myositis · 研飞ivySCI

  https://www.ivysci.com/articles/7573626__Epidemiology_of_myositis

  Epidemiology of myositis […] Purpose of review This review aims to synthesize recent developments in the epidemiology of idiopathic inflammatory myopathies (IIMs), focusing on incidence, prevalence, disease classification, and clinical outcomes. […] Recent findings IIM is a rare group of autoimmune diseases characterized by muscle weakness and systemic involvement, with incidence rates ranging from 0.2 to 2 cases per 100 000 person-years. […] Continued epidemiological research is essential to elucidate underlying mechanisms and inform future interventions, ultimately aiming to enhance the quality of life and clinical outcomes for affected patients.

• #6 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #7 Epidemiology, Survival, and Clinical Characteristics of Inclusion Body Myositis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9541152/

  We performed a populationbased study on inclusion body myositis with the primary aims to define the prevalence, survival rate, and incidence, and to investigate the symptom profiles associated with disease duration and sex over a 33year period. […] We identified 128 patients, 89 men and 39 women, with the strict clinicopathological definition of inclusion body myositis. The prevalence was 32 per million inhabitants, 19 per million women and 45 per million men, by December 31, 2017. Mean incidence was 2.5 per million inhabitants and year. […] Inclusion body myositis is an autoimmune disease with decreased survival rate and with marked sex differences in both prevalence and clinical manifestations. […] We aimed to describe the epidemiological data of IBM, including survival, prevalence, and incidence in a retrospective study covering 33years, in a welldefined region where most of the patients with IBM probably have been identified.

• #8

  https://link.springer.com/article/10.1007/s00415-022-11459-3

  Inclusion body myositis (IBM) is the most common acquired myopathy above 50 years of age with a variable prevalence of 50180 per million in this age group, depending on geography and ethnicity. […] However, these numbers are thought to be underestimations in particularly due to misdiagnosis. […] In view of the reported diagnostic delay of 56 years in IBM, more disease awareness is urgently needed to promote early diagnosis making. […] In the hope of increasing therapeutic possibilities in rare diseases such as IBM, early detection of affected patients is as essential for clinical trials as it is for clinical practice. […] Genetic investigations do not only contribute to the better understanding of disease pathomechanism and the development of potential new treatment strategies but can also serve to improve diagnosis making.

• #9 Incidence and prevalence of idiopathic inflammatory myopathies in Thailand from the Ministry of Public Health data analysis | Scientific Reports

  https://www.nature.com/articles/s41598-024-71633-7

  The epidemiology of idiopathic inflammatory myopathies (IIMs) varies by country. […] We aimed to assess the prevalence and incidence of IIM in the Thai population between 2017 and 2020. […] The prevalence and incidence of IIMs were analyzed with their 95% confidence intervals (CIs) and then categorized by sex and region. […] In 2017, the IIM cases numbered 9,074 among 65,204,797 Thais, resulting in a prevalence of 13.9 per 100,000 population (95% CI 13.6-14.2). […] Between 2018 and 2020, the incidence of IIMs slightly declined from 5.09 (95% CI 4.9-5.27) in 2017 and 4.92 (95% CI 4.7-5.10) in 2019 to 4.43 (95% CI 4.2-4.60) per 100,000 person-years in 2020. […] The majority of cases occurred in southern Thailand, with incidence rates of 7.60, 8.34, and 8.74 per 100,000 person-years.

• #10 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #11 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #12 Polymyositis: Practice Essentials, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/335925-overview

  Idiopathic inflammatory myopathies are relatively rare diseases, with an incidence in the United States that ranges from 0.5-8.4 cases per million population. Polymyositis is more common in the United States within the Black population, with the estimated Black-to-White incidences for polymyositis and dermatomyositis being 5:1 and 3:1, respectively. Internationally, polymyositis is less common among the Japanese. […] Polymyositis and dermatomyositis are more common in women than in men (2:1 ratio), while inclusion body myositis is twice as common in men. […] Polymyositis usually affects adults older than 20 years, especially those aged 45-60 years. Polymyositis rarely affects children. The age of onset of polymyositis with another collagen vascular disease is related to the associated condition. […] Five-year survival rates in polymyositis have been estimated at more than 80%. Mortality is most often related to associated malignancy or pulmonary complications; elderly patients with cardiac involvement or dysphagia also have a higher mortality rate.

• #13 Orphanet: Inclusion body myositis

  https://www.orpha.net/en/disease/detail/611

  Inclusion body myositis (IBM) has a highly variable prevalence according to geographic, ethnic and age criteria. Prevalence in the general population ranges from 1/14,000-1,000,000 but a three-fold increase is observed when considering only a population over 50 years. […] Underdiagnosis may be an explanation for the high ethno-geographic variation. […] Male-to-female ratio is 2:1 on average (but varies between 0.5 to 6.5:1).

• #14 Inclusion body myositis – Wikipedia

  https://en.wikipedia.org/wiki/Inclusion_body_myositis

  Prevalence of disease in a rigorous meta-analysis in 2017 was 46 patients per million. […] The earliest published prevalence was in 2000 and put at 5 per million. […] A 2017 study in Ireland reported 112 per million. […] It is not believed that the disease prevalence is increasing with time, but rather diagnostics and reporting are improving. […] Estimates of the mean age of onset range from 61 to 68 years old.

• #15 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #16 Idiopathic inflammatory myopathies – Knowledge @ AMBOSS

  https://www.amboss.com/us/knowledge/idiopathic-inflammatory-myopathies/

  Epidemiology […] – Incidence […] – PM and DM: 2/100,000 per year […] – In the US, PM disproportionately affects the black population. […] – Sex […] – PM and DM: (2:1) […] – IBM: (2:1) […] – Peak incidence […] – PM: 30-60 years […] – DM […] – 5-15 years (juvenile dermatomyositis) […] – 40-60 years (adult dermatomyositis) […] – IBM: 50 years […] Epidemiological data refers to the US, unless otherwise specified.

• #17 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #18 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #19 Inclusion body myositis – Wikipedia

  https://en.wikipedia.org/wiki/Inclusion_body_myositis

  Prevalence of disease in a rigorous meta-analysis in 2017 was 46 patients per million. […] The earliest published prevalence was in 2000 and put at 5 per million. […] A 2017 study in Ireland reported 112 per million. […] It is not believed that the disease prevalence is increasing with time, but rather diagnostics and reporting are improving. […] Estimates of the mean age of onset range from 61 to 68 years old.

• #20 Early-Onset Inclusion Body Myositis: Youth May Not Be Protective – Dermatomyositis and Other Inflammatory Myopathies

  https://www.medpagetoday.com/resource-centers/dermatomyositis-other-inflammatory-myopathies/early-onset-inclusion-body-myositis-youth-may-not-protective/4708

  A recent study reveals that early-onset inclusion body myositis (IBM) presents as a severe inflammatory muscle condition in younger individuals, challenging traditional age-centric diagnostic criteria and revealing significant mitochondrial DNA mutations that suggest accelerated muscle aging. […] In the current study, published online ahead of print in the Journal of Neurology, Dr. Lindgren and colleagues “aimed to describe epidemiology, survival, clinical parameters including progression of weakness, and mitochondrial pathology in patients with early-onset IBM.” […] This study provides a comprehensive examination of individuals with early-onset IBM, setting its findings against the context of a larger group diagnosed with clinicopathological IBM. […] The age-centric criteria for diagnosing IBM was found to be generally justified, with early-onset IBM proving less prevalent than clinicopathological IBM.

• #21 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #22 Polymyositis: Practice Essentials, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/335925-overview

  Idiopathic inflammatory myopathies are relatively rare diseases, with an incidence in the United States that ranges from 0.5-8.4 cases per million population. Polymyositis is more common in the United States within the Black population, with the estimated Black-to-White incidences for polymyositis and dermatomyositis being 5:1 and 3:1, respectively. Internationally, polymyositis is less common among the Japanese. […] Polymyositis and dermatomyositis are more common in women than in men (2:1 ratio), while inclusion body myositis is twice as common in men. […] Polymyositis usually affects adults older than 20 years, especially those aged 45-60 years. Polymyositis rarely affects children. The age of onset of polymyositis with another collagen vascular disease is related to the associated condition. […] Five-year survival rates in polymyositis have been estimated at more than 80%. Mortality is most often related to associated malignancy or pulmonary complications; elderly patients with cardiac involvement or dysphagia also have a higher mortality rate.

• #23 Orphanet: Inclusion body myositis

  https://www.orpha.net/en/disease/detail/611

  Inclusion body myositis (IBM) has a highly variable prevalence according to geographic, ethnic and age criteria. Prevalence in the general population ranges from 1/14,000-1,000,000 but a three-fold increase is observed when considering only a population over 50 years. […] Underdiagnosis may be an explanation for the high ethno-geographic variation. […] Male-to-female ratio is 2:1 on average (but varies between 0.5 to 6.5:1).

• #24 Orphanet: Inclusion body myositis

  https://www.orpha.net/en/disease/detail/611

  Inclusion body myositis (IBM) has a highly variable prevalence according to geographic, ethnic and age criteria. Prevalence in the general population ranges from 1/14,000-1,000,000 but a three-fold increase is observed when considering only a population over 50 years. […] Underdiagnosis may be an explanation for the high ethno-geographic variation. […] Male-to-female ratio is 2:1 on average (but varies between 0.5 to 6.5:1).

• #25 Inflammatory Myositis – Epidemiology Forecast – 2034

  https://www.researchandmarkets.com/reports/6027154/inflammatory-myositis-epidemiology-forecast?srsltid=AfmBOor4-5IXbPWl04o6HjjYmkEfmN7odXpIwIL-acMBx2FgAbOlS3Df

  The analyst projects that among the total diagnosed prevalent cases of Inflammatory Myositis in 7MM approximately 49% of cases were from the US. As per our estimations, in 2022, the EU4 and the UK accounted for nearly 68 thousand diagnosed prevalent cases of Inflammatory Myositis. […] According to the analysis, Inflammatory Myositis was diagnosed in approximately 65% of females and 35% of males within the 7MM in 2022. This analysis indicates a higher prevalence of Inflammatory Myositis among females than males. […] The highest proportion of Inflammatory Myositis cases was estimated in the 45-64 years in the 7MM, with an estimated ~78 thousand cases, while the least cases were in the age group 0-17 years (~7 thousand cases). […] For the purpose of designing the patient-based model for Inflammatory Myositis (OSA), the report provides historical as well as forecasted epidemiology segmented by Total Diagnosed Prevalent Cases of Inflammatory Myositis, Type-specific Diagnosed Prevalent cases of Inflammatory Myositis, Gender-specific Diagnosed Prevalent cases of Inflammatory Myositis, Age-specific Diagnosed Prevalent cases of Inflammatory Myositis, in the 7MM covering the United States, EU4 countries (Germany, France, Italy, and Spain) and the United Kingdom, and Japan, from 2020 to 2034. As per estimations, the total diagnosed prevalent cases of Inflammatory Myositis in the 7MM were approximately 184 thousand cases in 2022 and are projected to increase during the forecast period.

• #26 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #27 Disease IIMs – ERN ReCONNET | European Reference Network on Rare and Complex Connective Tissue and Musculoskeletal Diseases

  https://reconnet.ern-net.eu/disease-iims/

  IIMs incidence is about 8 cases per million inhabitants per year. […] It has increased during the last 50 years, which may reflect progress in diagnostic performance but also true modification of the epidemiology. […] Adult onset is about 10-fold more frequent than juvenile onset. […] Women are about 2-fold more frequently affected than men.

• #28 Disease IIMs – ERN ReCONNET | European Reference Network on Rare and Complex Connective Tissue and Musculoskeletal Diseases

  https://reconnet.ern-net.eu/disease-iims/

  IIMs incidence is about 8 cases per million inhabitants per year. […] It has increased during the last 50 years, which may reflect progress in diagnostic performance but also true modification of the epidemiology. […] Adult onset is about 10-fold more frequent than juvenile onset. […] Women are about 2-fold more frequently affected than men.

• #29 Incidence and prevalence of idiopathic inflammatory myopathies in Thailand from the Ministry of Public Health data analysis | Scientific Reports

  https://www.nature.com/articles/s41598-024-71633-7

  The incidence of IIMs decreased between 2019 and 2020, most likely due to the COVID-19 pandemic, which reduced reports and investigations. […] The current study determined that the prevalence of IIMs among Thais was similar to that of the majority of IIMs worldwide, with a rate of 13.93 per 100,000 (95 percent CI 13.6-14.21) in 2017. […] Our study reveals a decline in the incidence of IIMs among Thais from 2017 to 2020. […] The decrease in the number of new cases from 2019 to 2020 could be attributed to the COVID-19 pandemic, which resulted in fewer reported cases and investigations involving IIMs. […] Female cases predominate among IIMs in Thailand, which is consistent with previous research. […] Our research revealed that the peak prevalence of IIMs occurs between 60 and 69 years. […] The presence of IIMs in Thailand is unusual. […] It peaks among people aged 60 to 69, especially in southern Thailand. […] Furthermore, the frequency of IIM cases decreased significantly between 2019 and 2020, which was most likely influenced by the COVID-19 pandemic.

• #30 Orphanet: Inclusion body myositis

  https://www.orpha.net/en/disease/detail/611

  Inclusion body myositis (IBM) has a highly variable prevalence according to geographic, ethnic and age criteria. Prevalence in the general population ranges from 1/14,000-1,000,000 but a three-fold increase is observed when considering only a population over 50 years. […] Underdiagnosis may be an explanation for the high ethno-geographic variation. […] Male-to-female ratio is 2:1 on average (but varies between 0.5 to 6.5:1).

• #31 Epidemiology of Dermatomyositis | SpringerLink

  https://link.springer.com/chapter/10.1007/978-3-540-79313-7_5

  The idiopathic inflammatory myopathies are relatively rare diseases that occur throughout the world. The occurrence of DM/PM is uncommon. The absence of reliable epidemiologic data for DM is rather surprising and may relate to several reasons: (i) the rarity of disease, (ii) the lack of consistent use of diagnostic criteria, (iii) the indolent clinical course, (iv) the fact that the numbers result from studies on hospitalized patients, (v) the management of outpatients by physicians from many different specialties (including pediatric and adult rheumatologists, neurologists, dermatologists, other specialists, and general practitioners), and (vi) the lack of prospective studies of associated myositis in connective tissue disease. […] Dermatomyositis affects both children and adults. The incidence of DM is approximately 1020 times lower than the incidence of lupus erythematosus, or other connective tissue diseases systemic sclerosis or rheumatoid polyarthritis. The relative prevalence of DM in relation to PM varies between different studies.

• #32 Diagnostic delay of myositis: an integrated systematic review | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-022-02570-9

  The overall pooled mean diagnostic delay for IIM was (27.91 months or 2.25 years, 95% CI 15.0340.79 months, I2=99%) and is similar to other rheumatologic diseases with long diagnostic delay. […] We found longer diagnostic delay in gatekeeper health systems when compared with non-gatekeeper health systems, indicating that the difference in accessibility to specialists influences time to diagnosis. […] There were no differences in diagnostic delay between studies where MSA was tested and those where MSA was not tested. […] The presence of complex clinical characteristics that were found to contribute to diagnostic delay were reported in relation to ASS (n=2), DM (n=2), IBM (n=6), and mixed IIM (n=1). […] We did not identify any qualitative studies examining how people with myositis experienced diagnostic delay. […] These outcomes highlight the critical need to improve awareness, understanding and diagnosis of IIM.

• #33

  https://link.springer.com/article/10.1007/s00415-022-11459-3

  Inclusion body myositis (IBM) is the most common acquired myopathy above 50 years of age with a variable prevalence of 50180 per million in this age group, depending on geography and ethnicity. […] However, these numbers are thought to be underestimations in particularly due to misdiagnosis. […] In view of the reported diagnostic delay of 56 years in IBM, more disease awareness is urgently needed to promote early diagnosis making. […] In the hope of increasing therapeutic possibilities in rare diseases such as IBM, early detection of affected patients is as essential for clinical trials as it is for clinical practice. […] Genetic investigations do not only contribute to the better understanding of disease pathomechanism and the development of potential new treatment strategies but can also serve to improve diagnosis making.

• #34 Inclusion Body Myositis – EyeWiki

  https://eyewiki.org/Inclusion_Body_Myositis

  The prevalence of IBM ranges from 4.9-10.7 per million and depends on geographic area, ethnicity, sex, and age. […] Due to the high rate of misdiagnosis and the average time of diagnosis being 5.2 years, the latest prevalence figure may be an underestimate. […] Symptom onset before age 60 occurs in 18 to 20 percent of patients. […] Unlike many other autoimmune diseases, this disease affects men more often than women with a reported male to female ratio of 3:1.

• #35 Myositis | Diagnosis & Disease Information

  https://www.rheumatologyadvisor.com/ddi/myositis/

  Myositis is rare, with an estimated prevalence of approximately 14 to 21 cases per 100,000 people in the United States. Inclusion body myositis is most common in older adults, occurring in approximately 18 per 100,000 people age 50 years and older (compared with 5 per 100,000 in the population overall). […] While IBM is more prevalent in older men than women, DM occurs more frequently in women and can affect individuals of any age. Dermatomyositis has an estimated prevalence of 13 cases per 100,000 people. Children and adolescents younger than age 18 years with myositis most commonly have JM, which presents similarly to adult DM (with rash). […] Polymyositis often is found in people age 21 years and older and more often in women than in men. Although historically NAM was grouped with PM, it is now recognized as a unique form of myositis.

• #36 Idiopathic Inflammatory Myositis Industry Assessment,

  https://www.globenewswire.com/news-release/2024/12/11/2995273/0/en/Idiopathic-Inflammatory-Myositis-Industry-Assessment-2020-2034-Breakthrough-Therapies-Dazukibart-and-Efgartigimod-Propel-Market-Expansion-Across-the-7MM.html

  According to the analyst’s estimates, in 2023, there were approximately 191,589 diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM. Of these, the United States accounted for 48% of the cases, while EU4 and the UK accounted for nearly 38% and Japan represented 14% of the cases, respectively. […] The total diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM were approximately 191,589 cases in 2023, which are expected to increase during the forecast period (2020-2034). […] In 2023, the US accounted for the highest diagnosed prevalent cases of idiopathic inflammatory myositis with approximately 91,734 cases, which are expected to increase by 2034. […] Among EU4 and the UK, Germany had the highest diagnosed prevalent cases of idiopathic inflammatory myositis with nearly 21,781 cases in 2023, followed by France with around 17,475 cases. On the other hand, Spain accounted for the least with nearly 6,235 cases.

• #37 Idiopathic Inflammatory Myositis Industry Assessment,

  https://www.globenewswire.com/news-release/2024/12/11/2995273/0/en/Idiopathic-Inflammatory-Myositis-Industry-Assessment-2020-2034-Breakthrough-Therapies-Dazukibart-and-Efgartigimod-Propel-Market-Expansion-Across-the-7MM.html

  In 2023, Japan accounted for approximately 26,094 diagnosed prevalent cases of idiopathic inflammatory myositis which are expected to increase by 2034. […] In 2023, among the type specific diagnosed prevalent cases of idiopathic inflammatory myositis, the US accounted for approximately 30,649 cases for polymyositis, 38,517 cases for dermatomyositis, and 22,569 cases for inclusion body myositis. […] In 2023, Germany had approximately 8,712 males and 13,069 females diagnosed with idiopathic inflammatory myositis. […] In 2023, the diagnosed prevalent cases of idiopathic inflammatory myositis across the age groups 0-17 years, 18-44 years, 45-64 years, and 65 years and older were approximately 1,044, 7,959, 9,655, and 7,437, respectively, in Japan.

• #38 Epidemiology of sporadic inclusion body myositis and polymyositis in Olmsted County, Minnesota. | The Journal of Rheumatology

  https://www.jrheum.org/content/35/3/445

  OBJECTIVE: To determine the incidence and prevalence of sporadic inclusion body myositis (sIBM) and polymyositis (PM) in a population-based study. […] RESULTS: For sIBM, the age- and sex-adjusted incidence rates per 100,000 were 0.79 (95% confidence interval = 0.24-1.35), and for PM, 0.41 (95% CI 0.08-0.73). The age- and sex-adjusted prevalence rates per 100,000 were 7.06 (95% CI 0.87-13.24) for sIBM and 3.45 (95% CI 0.00-7.35) for PM. […] CONCLUSION: The incidence and prevalence rates for sIBM are higher than previously reported.

• #39 Autoimmune Myopathies – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532860/

  The estimated prevalence of polymyositis and dermatomyositis (PM/DM) is 5 to 22 per 100,000 persons, and the incidence is approximately 1.2 to 19 per million persons at risk per year. […] The incidence of myositis is increasing over time due to an increase in the detection rate. […] Dermatomyositis is bimodal in age distribution, with one peak at 5 to 15 years and another at 45 to 60 years. […] Polymyositis rarely occurs in the pediatric age group, and the mean age is between 50 and 60 years. […] The overall female-to-male incidence ratio is 2 to 3:1. […] In the United States, the Black race to White race ratio of incidence is 3 to 4:1. […] In Europe, the prevalence significantly increases from the north to the south, and this may be due to either environmental or genetic reasons.

• #40 Inflammatory Myositis – Epidemiology Forecast – 2034

  https://www.researchandmarkets.com/reports/6027154/inflammatory-myositis-epidemiology-forecast?srsltid=AfmBOor4-5IXbPWl04o6HjjYmkEfmN7odXpIwIL-acMBx2FgAbOlS3Df

  The analyst projects that among the total diagnosed prevalent cases of Inflammatory Myositis in 7MM approximately 49% of cases were from the US. As per our estimations, in 2022, the EU4 and the UK accounted for nearly 68 thousand diagnosed prevalent cases of Inflammatory Myositis. […] According to the analysis, Inflammatory Myositis was diagnosed in approximately 65% of females and 35% of males within the 7MM in 2022. This analysis indicates a higher prevalence of Inflammatory Myositis among females than males. […] The highest proportion of Inflammatory Myositis cases was estimated in the 45-64 years in the 7MM, with an estimated ~78 thousand cases, while the least cases were in the age group 0-17 years (~7 thousand cases). […] For the purpose of designing the patient-based model for Inflammatory Myositis (OSA), the report provides historical as well as forecasted epidemiology segmented by Total Diagnosed Prevalent Cases of Inflammatory Myositis, Type-specific Diagnosed Prevalent cases of Inflammatory Myositis, Gender-specific Diagnosed Prevalent cases of Inflammatory Myositis, Age-specific Diagnosed Prevalent cases of Inflammatory Myositis, in the 7MM covering the United States, EU4 countries (Germany, France, Italy, and Spain) and the United Kingdom, and Japan, from 2020 to 2034. As per estimations, the total diagnosed prevalent cases of Inflammatory Myositis in the 7MM were approximately 184 thousand cases in 2022 and are projected to increase during the forecast period.

• #41 Inflammatory Myositis – Epidemiology Forecast – 2034

  https://www.researchandmarkets.com/reports/6027154/inflammatory-myositis-epidemiology-forecast?srsltid=AfmBOor4-5IXbPWl04o6HjjYmkEfmN7odXpIwIL-acMBx2FgAbOlS3Df

  The overall count of individuals diagnosed with Inflammatory Myositis in the United States was approximately 90 thousand in 2022, and it is expected to increase at an estimated CAGR throughout the study period (2020-2034). The anticipated future rise in Inflammatory Myositis cases may stem from factors like increased awareness, aging population, environmental triggers, genetic predisposition, autoimmune factors, improved survival, and changing lifestyles. […] Among the 7MM, EU4 and the UK accounted for nearly 37% diagnosed prevalent cases of Inflammatory Myositis, and these cases are expected to increase during the forecast period (2023-2034). […] Among EU4 and the UK, Germany had the highest diagnosed prevalent population of Inflammatory Myositis, accounting to 32%, followed by the Italy (22%) and the UK (20%) in 2022. On the other hand, Spain had the lowest diagnosed prevalent population in EU4 and the UK in 2022.

• #42 Idiopathic Inflammatory Myositis Industry Assessment,

  https://www.globenewswire.com/news-release/2024/12/11/2995273/0/en/Idiopathic-Inflammatory-Myositis-Industry-Assessment-2020-2034-Breakthrough-Therapies-Dazukibart-and-Efgartigimod-Propel-Market-Expansion-Across-the-7MM.html

  According to the analyst’s estimates, in 2023, there were approximately 191,589 diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM. Of these, the United States accounted for 48% of the cases, while EU4 and the UK accounted for nearly 38% and Japan represented 14% of the cases, respectively. […] The total diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM were approximately 191,589 cases in 2023, which are expected to increase during the forecast period (2020-2034). […] In 2023, the US accounted for the highest diagnosed prevalent cases of idiopathic inflammatory myositis with approximately 91,734 cases, which are expected to increase by 2034. […] Among EU4 and the UK, Germany had the highest diagnosed prevalent cases of idiopathic inflammatory myositis with nearly 21,781 cases in 2023, followed by France with around 17,475 cases. On the other hand, Spain accounted for the least with nearly 6,235 cases.

• #43 FRI0447 Epidemiology of idiopathic inflammatory myopathies in england – a database analysis | Annals of the Rheumatic Diseases

  https://ard.bmj.com/content/71/Suppl_3/465.3

  The idiopathic inflammatory myopathies (IIM) are a rare, heterogeneous group of autoimmune muscle disorders, including dermatomyositis (DM), polymyositis (PM), and inclusion body myositis. Data on the epidemiology of IIM are limited and quite variable with the reported incidence and prevalence ranging from 0.4 to 5.8 per 100,000 person-years (PY) and 3.5 to 25.0 per 100,000 population, respectively. […] To describe the epidemiology of IIM patients in England using medical record databases. […] From 2000-2009, 326 incident IIM cases were identified of which 62% were female and 81% were in those 45 years of age or older. The overall incidence of IIM was 1.9/100,000 PY (95% CI: 1.7-2.1/100,000 PY) ranging from 1.6 in 2000 to 2.0 in 2009. […] There were 465 prevalent IIM cases identified in 2009 corresponding to the overall prevalence of 27.2/100,000 people (95% CI: 24.8-29.8/100,000 people). The prevalence was positively associated with female gender and older age. […] In 2009, the hospitalization rate for IIM was 5.6 per 100,000 in the general populations. […] We found a higher IIM prevalence in England than previously reported in other countries. Studies that confirm the electronic diagnoses are needed to validate the findings.

• #44 Idiopathic Inflammatory Myositis Industry Assessment,

  https://www.globenewswire.com/news-release/2024/12/11/2995273/0/en/Idiopathic-Inflammatory-Myositis-Industry-Assessment-2020-2034-Breakthrough-Therapies-Dazukibart-and-Efgartigimod-Propel-Market-Expansion-Across-the-7MM.html

  According to the analyst’s estimates, in 2023, there were approximately 191,589 diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM. Of these, the United States accounted for 48% of the cases, while EU4 and the UK accounted for nearly 38% and Japan represented 14% of the cases, respectively. […] The total diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM were approximately 191,589 cases in 2023, which are expected to increase during the forecast period (2020-2034). […] In 2023, the US accounted for the highest diagnosed prevalent cases of idiopathic inflammatory myositis with approximately 91,734 cases, which are expected to increase by 2034. […] Among EU4 and the UK, Germany had the highest diagnosed prevalent cases of idiopathic inflammatory myositis with nearly 21,781 cases in 2023, followed by France with around 17,475 cases. On the other hand, Spain accounted for the least with nearly 6,235 cases.

• #45 Idiopathic Inflammatory Myositis Industry Assessment,

  https://www.globenewswire.com/news-release/2024/12/11/2995273/0/en/Idiopathic-Inflammatory-Myositis-Industry-Assessment-2020-2034-Breakthrough-Therapies-Dazukibart-and-Efgartigimod-Propel-Market-Expansion-Across-the-7MM.html

  In 2023, Japan accounted for approximately 26,094 diagnosed prevalent cases of idiopathic inflammatory myositis which are expected to increase by 2034. […] In 2023, among the type specific diagnosed prevalent cases of idiopathic inflammatory myositis, the US accounted for approximately 30,649 cases for polymyositis, 38,517 cases for dermatomyositis, and 22,569 cases for inclusion body myositis. […] In 2023, Germany had approximately 8,712 males and 13,069 females diagnosed with idiopathic inflammatory myositis. […] In 2023, the diagnosed prevalent cases of idiopathic inflammatory myositis across the age groups 0-17 years, 18-44 years, 45-64 years, and 65 years and older were approximately 1,044, 7,959, 9,655, and 7,437, respectively, in Japan.

• #46 :: JKMS :: Journal of Korean Medical Science

  https://jkms.org/DOIx.php?id=10.3346/jkms.2019.34.e55

  Using a nationwide population-based database that included most of the Korean population, we estimated an overall IIM prevalence rate of 2.34.4/100,000 persons and an incidence of 2.95.2 per 1,000,000. […] We did not observe any trends in incidence over a 10-year period. […] Our calculated prevalence and incidence were lower than those reported in a recent study from Sweden between 2007 and 2011 (prevalence of 14/100,000 and incidence of 11/1,000,000) and a meta-analysis of prevalence (14/100,000 between 1982 and 2010 and incidence 7.98/1,000,000 between 1951 and 2010). […] In conclusion, our study observed a slightly lower prevalence and incidence of IIM in Korea compared to recent reports from other countries. More than two-thirds of patients had more than two comorbidities.

• #47 Incidence and prevalence of idiopathic inflammatory myopathies in Thailand from the Ministry of Public Health data analysis | Scientific Reports

  https://www.nature.com/articles/s41598-024-71633-7

  The epidemiology of idiopathic inflammatory myopathies (IIMs) varies by country. […] We aimed to assess the prevalence and incidence of IIM in the Thai population between 2017 and 2020. […] The prevalence and incidence of IIMs were analyzed with their 95% confidence intervals (CIs) and then categorized by sex and region. […] In 2017, the IIM cases numbered 9,074 among 65,204,797 Thais, resulting in a prevalence of 13.9 per 100,000 population (95% CI 13.6-14.2). […] Between 2018 and 2020, the incidence of IIMs slightly declined from 5.09 (95% CI 4.9-5.27) in 2017 and 4.92 (95% CI 4.7-5.10) in 2019 to 4.43 (95% CI 4.2-4.60) per 100,000 person-years in 2020. […] The majority of cases occurred in southern Thailand, with incidence rates of 7.60, 8.34, and 8.74 per 100,000 person-years.

• #48 Inpatient Epidemiology of Dermatomyositis and Polymyositis in the United States – ACR Meeting Abstracts

  https://acrabstracts.org/abstract/inpatient-epidemiology-of-dermatomyositis-and-polymyositis-in-the-united-states/

  Inpatient Epidemiology of Dermatomyositis and Polymyositis in the United States […] Data on inpatient epidemiology, resource utilization, and healthcare expenditures of IIM are not well described. […] The aim of this study was to explore those characteristics using a large national inpatient database. […] The primary outcome was determining the inpatient prevalence of IIM. […] A total of 160,528 admissions of patients with a diagnosis of DM/PM occurred in the study period. […] For the primary outcome, the inpatient prevalence of DM/PM was 41.9 cases per 100,000 discharges. […] The inpatient prevalence of DM/PM was higher than what would be expected from the overall incidence. […] Hospitalizations of these patients were associated with a significantly higher morbidity and mortality. […] The mean total hospital costs, charges, and LOS for patients admitted with DM/PM were higher than patients without DM/PM.

• #49 Inpatient Epidemiology of Dermatomyositis and Polymyositis in the United States – ACR Meeting Abstracts

  https://acrabstracts.org/abstract/inpatient-epidemiology-of-dermatomyositis-and-polymyositis-in-the-united-states/

  Inpatient Epidemiology of Dermatomyositis and Polymyositis in the United States […] Data on inpatient epidemiology, resource utilization, and healthcare expenditures of IIM are not well described. […] The aim of this study was to explore those characteristics using a large national inpatient database. […] The primary outcome was determining the inpatient prevalence of IIM. […] A total of 160,528 admissions of patients with a diagnosis of DM/PM occurred in the study period. […] For the primary outcome, the inpatient prevalence of DM/PM was 41.9 cases per 100,000 discharges. […] The inpatient prevalence of DM/PM was higher than what would be expected from the overall incidence. […] Hospitalizations of these patients were associated with a significantly higher morbidity and mortality. […] The mean total hospital costs, charges, and LOS for patients admitted with DM/PM were higher than patients without DM/PM.

• #50 Cost of illness in inclusion body myositis: results from a cross-sectional study in Germany | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-023-02902-3

  The aim of this study is twofold: first, it is to assess the direct and indirect costs per year in IBM in Germany for the reference year 2021 from a societal perspective. Second, it is to identify and understand the impact of potential cost driving factors. […] We estimated the mean total annual per capita COI of US$102,682 (95% CI US$82,763US$123,090) in 2021. […] Significant differences in total COI were identified for the degree of disability, marital and employment status. […] We identified remarkable and heterogenous cost in IBM. […] The high consumption of informal care causes for 82.9% of direct nonmedical costs. […] The total national COI were 31.6 million up to 158.1 million (US$42.7 millionUS$213.7 million). […] This is the first study to estimate the IBM related indirect and direct costs in Germany. […] Our results demonstrate the financial burden of IBM, that is comparable to other severe NMD like SMA, DMD or BMD.

• #51 Cost of illness in inclusion body myositis: results from a cross-sectional study in Germany | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-023-02902-3

  The aim of this study is twofold: first, it is to assess the direct and indirect costs per year in IBM in Germany for the reference year 2021 from a societal perspective. Second, it is to identify and understand the impact of potential cost driving factors. […] We estimated the mean total annual per capita COI of US$102,682 (95% CI US$82,763US$123,090) in 2021. […] Significant differences in total COI were identified for the degree of disability, marital and employment status. […] We identified remarkable and heterogenous cost in IBM. […] The high consumption of informal care causes for 82.9% of direct nonmedical costs. […] The total national COI were 31.6 million up to 158.1 million (US$42.7 millionUS$213.7 million). […] This is the first study to estimate the IBM related indirect and direct costs in Germany. […] Our results demonstrate the financial burden of IBM, that is comparable to other severe NMD like SMA, DMD or BMD.

• #52 Myositis – WikiMSK

  https://wikimsk.org/wiki/Myositis

  The incidence is approximately 1-6 per 100,000. There is a 2:1 female to male prevalence. Myositis can occur in all ages. In 20% there is an association with other autoimmune diseases, called overlap myositis, especially RA, SLE, and MCTD. In the elderly, dermatomyositis and polymyositis are often paraneoplastic, and symptoms can occur before tumour detection. […] The original Bohan and Peter classification which includes 5 groups from 1975 has been the most widely used classification criteria. […] Muscle biopsies can provide valuable diagnostic information in patients with suspected autoimmune muscle disease. Bohan and Peter identified several features that are commonly associated with autoimmune myopathies, including degenerating and/or necrotic myofibers, regenerating muscle fibers, atrophic muscle cells, and evidence of inflammatory exudates. However, these features are not specific to autoimmune myopathies and can also be found in other conditions such as IBM and inflammatory muscular dystrophies.

• #53 Inclusion body myositis | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/inclusion-body-myositis?lang=us

  Inclusion body myositis tends to occur in older individuals, often after the age of 50, although the disease may occasionally present earlier. It is more common in males (M:F up to 3:1). […] Recognized associations include diabetes mellitus: ~20%, other autoimmune conditions (e.g. Sjgren syndrome): ~15%, malignancy (e.g. T cell large granular lymphocytic leukemia).

• #54 :: JKMS :: Journal of Korean Medical Science

  https://jkms.org/DOIx.php?id=10.3346/jkms.2019.34.e55

  Using a nationwide population-based database that included most of the Korean population, we estimated an overall IIM prevalence rate of 2.34.4/100,000 persons and an incidence of 2.95.2 per 1,000,000. […] We did not observe any trends in incidence over a 10-year period. […] Our calculated prevalence and incidence were lower than those reported in a recent study from Sweden between 2007 and 2011 (prevalence of 14/100,000 and incidence of 11/1,000,000) and a meta-analysis of prevalence (14/100,000 between 1982 and 2010 and incidence 7.98/1,000,000 between 1951 and 2010). […] In conclusion, our study observed a slightly lower prevalence and incidence of IIM in Korea compared to recent reports from other countries. More than two-thirds of patients had more than two comorbidities.

• #55 Epidemiology, Survival, and Clinical Characteristics of Inclusion Body Myositis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9541152/

  In this study, we analyzed epidemiological and clinical aspects of IBM in Region Vstra Gtaland, Sweden using a populationbased approach. We identified 128 patients with clinicopathological IBM and 14 patients with clinically defined or probable IBM diagnosed between 1985 and 2017. […] A relative overestimation of autoimmune diseases in our study is possible, but a majority of the reported autoimmune diseases leads to medical treatment and are probably correctly registered. This suggests that autoimmune diseases are more common in patients with IBM than in the general population, supporting the concept that IBM is an autoimmune disease.

• #56 Myositis – WikiMSK

  https://wikimsk.org/wiki/Myositis

  The incidence is approximately 1-6 per 100,000. There is a 2:1 female to male prevalence. Myositis can occur in all ages. In 20% there is an association with other autoimmune diseases, called overlap myositis, especially RA, SLE, and MCTD. In the elderly, dermatomyositis and polymyositis are often paraneoplastic, and symptoms can occur before tumour detection. […] The original Bohan and Peter classification which includes 5 groups from 1975 has been the most widely used classification criteria. […] Muscle biopsies can provide valuable diagnostic information in patients with suspected autoimmune muscle disease. Bohan and Peter identified several features that are commonly associated with autoimmune myopathies, including degenerating and/or necrotic myofibers, regenerating muscle fibers, atrophic muscle cells, and evidence of inflammatory exudates. However, these features are not specific to autoimmune myopathies and can also be found in other conditions such as IBM and inflammatory muscular dystrophies.

• #57 Update on Malignancy in Myositis—Well-Established Association with Unmet Needs

  https://www.mdpi.com/2218-273X/12/1/111

  The highest risk of malignancy is observed in the course of dermatomyositis. […] Increased risk of neoplasm is also observed in individuals with polymyositis, yet it is not as high as in dermatomyositis. […] According to the meta-analysis of five studies on the total group of 4538 patients with myositis, the overall relative risk for developing malignancy was 4.66 for patients with dermatomyositis and 1.75 for patients with polymyositis. […] The above data prove that cancer risk is not uniformly increased for all patients with IIM. […] The highest risk exists around the time of IIM diagnosis. […] Individual factors, such as the patient’s age and the subtypes of the disease, also impact the risk.

• #58 Update on Malignancy in Myositis—Well-Established Association with Unmet Needs

  https://www.mdpi.com/2218-273X/12/1/111

  Idiopathic inflammatory myopathies are a group of rare connective tissue diseases with a well-documented association with malignancy. […] The article summarizes the current state of knowledge on the epidemiology and pathogenesis of CAM. […] The definition of CAM has been based on numerous epidemiological observations. […] The newest population-based studies confirm that the majority of malignancies occur in the temporal association with the onset of myopathy. […] Most of the cancer cases emerge within a year of IIM diagnosis, and the risk of malignancy decreases over time. […] According to the EuroMyositis registry, malignancies occurred at any time in 13% of patients with myositis, with most of them being diagnosed in close temporal association with the onset of myopathy. […] In most cases, cancer develops simultaneously with the onset of myopathy or within the first year of diagnosis, but the risk, although gradually decreasing, remains elevated for several years.

• #59 Update on Malignancy in Myositis—Well-Established Association with Unmet Needs

  https://www.mdpi.com/2218-273X/12/1/111

  Idiopathic inflammatory myopathies are a group of rare connective tissue diseases with a well-documented association with malignancy. […] The article summarizes the current state of knowledge on the epidemiology and pathogenesis of CAM. […] The definition of CAM has been based on numerous epidemiological observations. […] The newest population-based studies confirm that the majority of malignancies occur in the temporal association with the onset of myopathy. […] Most of the cancer cases emerge within a year of IIM diagnosis, and the risk of malignancy decreases over time. […] According to the EuroMyositis registry, malignancies occurred at any time in 13% of patients with myositis, with most of them being diagnosed in close temporal association with the onset of myopathy. […] In most cases, cancer develops simultaneously with the onset of myopathy or within the first year of diagnosis, but the risk, although gradually decreasing, remains elevated for several years.

• #60 International Guideline for Idiopathic Inflammatory Myopathy-Associated Cancer Screening: an International Myositis Assessment and Clinical Studies Group (IMACS) initiative | Nature Reviews Rheumatology

  https://www.nature.com/articles/s41584-023-01045-w

  Adult-onset idiopathic inflammatory myopathy (IIM) is associated with an increased cancer risk within the 3 years preceding and following IIM onset. […] Evidence suggests that up to one in four people with IIM are diagnosed with cancer within 3 years of IIM onset. […] Cancer remains the leading cause of death in adults with IIM, likely due in part to delayed diagnosis. […] IIM-associated cancers are overwhelmingly diagnosed at an advanced stage; a cohort study identified that 83% of IIM-associated cancers were stage III or IV at the time of diagnosis and were associated with a cancer remission rate of only 17%. […] Early detection of cancer is key to improving outcomes. […] The International Myositis Assessment and Clinical Studies Group (IMACS) sponsored a project to develop evidence- and consensus-based cancer screening recommendations for patients with IIM.

• #61 International Guideline for Idiopathic Inflammatory Myopathy-Associated Cancer Screening: an International Myositis Assessment and Clinical Studies Group (IMACS) initiative | Nature Reviews Rheumatology

  https://www.nature.com/articles/s41584-023-01045-w

  The Expert Group identified IIM subtypes, autoantibodies and clinical features associated with high, intermediate and low risk of IIM-associated cancer. […] The recommendations are aimed at facilitating earlier IIM-associated cancer detection, especially in those who are at a high risk, thus potentially improving outcomes, including survival. […] The recommendations provide practical guidance for clinicians serving IIM populations across varying countries and health systems. […] Implementation of the recommendations is aimed at facilitating early detection of IIM-associated cancer, especially in those at a high risk, thus potentially improving outcomes, including survival. […] The guideline standardizes patient care and provides a foundation upon which future IIM-cancer screening research can build.

• #62 Polymyositis: Practice Essentials, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/335925-overview

  Idiopathic inflammatory myopathies are relatively rare diseases, with an incidence in the United States that ranges from 0.5-8.4 cases per million population. Polymyositis is more common in the United States within the Black population, with the estimated Black-to-White incidences for polymyositis and dermatomyositis being 5:1 and 3:1, respectively. Internationally, polymyositis is less common among the Japanese. […] Polymyositis and dermatomyositis are more common in women than in men (2:1 ratio), while inclusion body myositis is twice as common in men. […] Polymyositis usually affects adults older than 20 years, especially those aged 45-60 years. Polymyositis rarely affects children. The age of onset of polymyositis with another collagen vascular disease is related to the associated condition. […] Five-year survival rates in polymyositis have been estimated at more than 80%. Mortality is most often related to associated malignancy or pulmonary complications; elderly patients with cardiac involvement or dysphagia also have a higher mortality rate.

• #63 Epidemiology, Survival, and Clinical Characteristics of Inclusion Body Myositis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9541152/

  On December 31, 2017, the prevalence of clinicopathological IBM in VGR was 31.9 patients per million inhabitants and the total prevalence including clinically defined and probable IBM was 33.7 patients per million inhabitants. The mean incidence of clinicopathological IBM during the studied time period was 2.5 patients per million inhabitants and year. […] The survival rate in IBM has been debated and several earlier studies have not been able to demonstrate any effect of IBM on survival. […] In our study, the so far largest populationbased study of survival, including for each of the 128 patients 85 to 11,866 matched controls, we show a decreased cumulative survival in patients with IBM, both from diagnosis date and symptom onset. […] Our results suggest that women are affected by dysphagia earlier in the disease course and more frequently than men, whereas quadriceps muscle weakness is a more common early symptom among men.

• #64 Epidemiology, Survival, and Clinical Characteristics of Inclusion Body Myositis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC9541152/

  On December 31, 2017, the prevalence of clinicopathological IBM in VGR was 31.9 patients per million inhabitants and the total prevalence including clinically defined and probable IBM was 33.7 patients per million inhabitants. The mean incidence of clinicopathological IBM during the studied time period was 2.5 patients per million inhabitants and year. […] The survival rate in IBM has been debated and several earlier studies have not been able to demonstrate any effect of IBM on survival. […] In our study, the so far largest populationbased study of survival, including for each of the 128 patients 85 to 11,866 matched controls, we show a decreased cumulative survival in patients with IBM, both from diagnosis date and symptom onset. […] Our results suggest that women are affected by dysphagia earlier in the disease course and more frequently than men, whereas quadriceps muscle weakness is a more common early symptom among men.

• #65 Early-Onset Inclusion Body Myositis: Youth May Not Be Protective – Dermatomyositis and Other Inflammatory Myopathies

  https://www.medpagetoday.com/resource-centers/dermatomyositis-other-inflammatory-myopathies/early-onset-inclusion-body-myositis-youth-may-not-protective/4708

  This study also highlighted intriguing mitochondrial changes in early-onset IBM, suggesting the muscle disease itself might cause mtDNA rearrangements. These findings indicate the possibility of accelerated muscle aging in IBM. […] “In conclusion, early-onset IBM is a severe inflammatory myopathy with a high mitochondrial DNA mutation load in muscle fibers, causing progressive muscle weakness and a reduced cumulative survival in young and middle-aged individuals,” the authors wrote in the Journal of Neurology.

• #66 Epidemiology and clinical outcome and its main determinants among patients with inflammatory myositis – Health Science Monitor

  http://hsm.umsu.ac.ir/browse.php?a_code=A-10-105-1&slc_lang=en&sid=1

  Epidemiology and clinical outcome and its main determinants among patients with inflammatory myositis. […] Despite the proper understanding of pathophysiological aspects and recent development in therapeutic approaches, the outcome of patients suffering from inflammatory myositis remains unsatisfactory. […] This study aimed to evaluate the outcome of patients with inflammatory myositis (response rate to treatment) and to determine the related and predictive factors of this outcome in these patients. […] Within the follow-up time, 40.0% were completely treated (complete remission), 3.8% had no proper response to treatment (incomplete remission), and 13.8% did not respond to the treatment. […] A notable number of inflammatory myositis patients still do not respond to routine treatment, and we, in fact, are at the forefront of managing the disease.

• #67 Epidemiology and clinical outcome and its main determinants among patients with inflammatory myositis – Health Science Monitor

  http://hsm.umsu.ac.ir/browse.php?a_code=A-10-105-1&slc_lang=en&sid=1

  Epidemiology and clinical outcome and its main determinants among patients with inflammatory myositis. […] Despite the proper understanding of pathophysiological aspects and recent development in therapeutic approaches, the outcome of patients suffering from inflammatory myositis remains unsatisfactory. […] This study aimed to evaluate the outcome of patients with inflammatory myositis (response rate to treatment) and to determine the related and predictive factors of this outcome in these patients. […] Within the follow-up time, 40.0% were completely treated (complete remission), 3.8% had no proper response to treatment (incomplete remission), and 13.8% did not respond to the treatment. […] A notable number of inflammatory myositis patients still do not respond to routine treatment, and we, in fact, are at the forefront of managing the disease.

• #68

  https://journals.lww.com/10.1097/BOR.0000000000001076

  This review aims to synthesize recent developments in the epidemiology of idiopathic inflammatory myopathies (IIMs), focusing on incidence, prevalence, disease classification, and clinical outcomes. […] IIM is a rare group of autoimmune diseases characterized by muscle weakness and systemic involvement, with incidence rates ranging from 0.2 to 2 cases per 100 000 person-years. […] Continued epidemiological research is essential to elucidate underlying mechanisms and inform future interventions, ultimately aiming to enhance the quality of life and clinical outcomes for affected patients.

• #69 Epidemiology of myositis · 研飞ivySCI

  https://www.ivysci.com/articles/7573626__Epidemiology_of_myositis

  Epidemiology of myositis […] Purpose of review This review aims to synthesize recent developments in the epidemiology of idiopathic inflammatory myopathies (IIMs), focusing on incidence, prevalence, disease classification, and clinical outcomes. […] Recent findings IIM is a rare group of autoimmune diseases characterized by muscle weakness and systemic involvement, with incidence rates ranging from 0.2 to 2 cases per 100 000 person-years. […] Continued epidemiological research is essential to elucidate underlying mechanisms and inform future interventions, ultimately aiming to enhance the quality of life and clinical outcomes for affected patients.

• #70 Diagnostic delay of myositis: an integrated systematic review | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-022-02570-9

  The overall pooled mean diagnostic delay for IIM was (27.91 months or 2.25 years, 95% CI 15.0340.79 months, I2=99%) and is similar to other rheumatologic diseases with long diagnostic delay. […] We found longer diagnostic delay in gatekeeper health systems when compared with non-gatekeeper health systems, indicating that the difference in accessibility to specialists influences time to diagnosis. […] There were no differences in diagnostic delay between studies where MSA was tested and those where MSA was not tested. […] The presence of complex clinical characteristics that were found to contribute to diagnostic delay were reported in relation to ASS (n=2), DM (n=2), IBM (n=6), and mixed IIM (n=1). […] We did not identify any qualitative studies examining how people with myositis experienced diagnostic delay. […] These outcomes highlight the critical need to improve awareness, understanding and diagnosis of IIM.

• #71

  https://link.springer.com/article/10.1007/s00415-022-11459-3

  Inclusion body myositis (IBM) is the most common acquired myopathy above 50 years of age with a variable prevalence of 50180 per million in this age group, depending on geography and ethnicity. […] However, these numbers are thought to be underestimations in particularly due to misdiagnosis. […] In view of the reported diagnostic delay of 56 years in IBM, more disease awareness is urgently needed to promote early diagnosis making. […] In the hope of increasing therapeutic possibilities in rare diseases such as IBM, early detection of affected patients is as essential for clinical trials as it is for clinical practice. […] Genetic investigations do not only contribute to the better understanding of disease pathomechanism and the development of potential new treatment strategies but can also serve to improve diagnosis making.

• #72

  https://link.springer.com/article/10.1007/s00415-022-11459-3

  Inclusion body myositis (IBM) is the most common acquired myopathy above 50 years of age with a variable prevalence of 50180 per million in this age group, depending on geography and ethnicity. […] However, these numbers are thought to be underestimations in particularly due to misdiagnosis. […] In view of the reported diagnostic delay of 56 years in IBM, more disease awareness is urgently needed to promote early diagnosis making. […] In the hope of increasing therapeutic possibilities in rare diseases such as IBM, early detection of affected patients is as essential for clinical trials as it is for clinical practice. […] Genetic investigations do not only contribute to the better understanding of disease pathomechanism and the development of potential new treatment strategies but can also serve to improve diagnosis making.

• #73

  https://link.springer.com/article/10.1007/s00415-022-11459-3

  Our study, currently with 1300 recruited sIBM cases, is the largest sIBM cohort to date. […] We expect to identify several sIBM genetic variants and locus that cluster in disease associated genes. […] The identification of associations with genes involved in immune or neurodegenerative pathways using WES and WEG could open a new treatment opportunity. […] Further improvement of current diagnostic criteria and the definition of potential genetic and/or laboratory biomarkers are necessary to improve diagnostic accuracy, reduce diagnostic delay and meet the therapeutic window of opportunity for immunomodulatory drugs at early disease stages.

• #74

  https://link.springer.com/article/10.1007/s00415-022-11459-3

  Our study, currently with 1300 recruited sIBM cases, is the largest sIBM cohort to date. […] We expect to identify several sIBM genetic variants and locus that cluster in disease associated genes. […] The identification of associations with genes involved in immune or neurodegenerative pathways using WES and WEG could open a new treatment opportunity. […] Further improvement of current diagnostic criteria and the definition of potential genetic and/or laboratory biomarkers are necessary to improve diagnostic accuracy, reduce diagnostic delay and meet the therapeutic window of opportunity for immunomodulatory drugs at early disease stages.

• #75 Inflammatory Myositis Market: Epidemiology, Therapies,

  https://www.openpr.com/news/3996156/inflammatory-myositis-market-epidemiology-therapies

  The inflammatory myositis therapeutics market is set to grow at a robust pace, with an estimated compound annual growth rate (CAGR) of around 11.7% across the 7MM. […] Inflammatory myositis market report covers a descriptive overview and comprehensive insight of the Inflammatory myositis Epidemiology and Inflammatory myositis market in the 7MM (the United States, EU5 (Germany, Spain, France, Italy, UK) Japan). […] The Inflammatory myositis market report provides insights into the current and emerging therapies. […] The inflammatory myositis market report provides a global historical and forecasted market covering drug outreach in 7MM.

• #76 Inflammatory Myositis Market: Epidemiology, Therapies,

  https://www.openpr.com/news/3996156/inflammatory-myositis-market-epidemiology-therapies

  Inflammatory myositis emerging therapies, such as Dazukibart (PF-06823859), and others, are expected to boost the Inflammatory myositis Market in the upcoming years. DelveInsight has launched a new report on „Inflammatory myositis – Market Insights, Epidemiology, and Market Forecast-2034” that delivers an in-depth understanding of the Inflammatory myositis, historical and forecasted epidemiology as well as the Inflammatory myositis market trends in the United States, EU5 (Germany, Spain, Italy, France, and United Kingdom) and Japan. […] The total market size of Inflammatory myositis in the 7MM is approximately USD 589 million in 2023 and is projected to increase during the forecast period (2024-2034). […] In 2023, the U.S. market for inflammatory myositis emerged as a key player among the seven major markets (7MM), reaching a notable valuation of USD 301 million.

• #77 Idiopathic Inflammatory Myositis Industry Assessment,

  https://www.globenewswire.com/news-release/2024/12/11/2995273/0/en/Idiopathic-Inflammatory-Myositis-Industry-Assessment-2020-2034-Breakthrough-Therapies-Dazukibart-and-Efgartigimod-Propel-Market-Expansion-Across-the-7MM.html

  According to the analyst’s estimates, in 2023, there were approximately 191,589 diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM. Of these, the United States accounted for 48% of the cases, while EU4 and the UK accounted for nearly 38% and Japan represented 14% of the cases, respectively. […] The total diagnosed prevalent cases of idiopathic inflammatory myositis in the 7MM were approximately 191,589 cases in 2023, which are expected to increase during the forecast period (2020-2034). […] In 2023, the US accounted for the highest diagnosed prevalent cases of idiopathic inflammatory myositis with approximately 91,734 cases, which are expected to increase by 2034. […] Among EU4 and the UK, Germany had the highest diagnosed prevalent cases of idiopathic inflammatory myositis with nearly 21,781 cases in 2023, followed by France with around 17,475 cases. On the other hand, Spain accounted for the least with nearly 6,235 cases.

• #78 Myositis ( – University of Manchester)

  http://research.bmh.manchester.ac.uk/CIGMR/research/autoimmune/Autoimmunity/Myositis/

  Unexplained inflammation in muscle, known as myositis, represents a difficult group of related disease, affecting about 10,000 people in the UK. […] Even between experts, there is lack of agreement how to diagnose and treat myositis. […] There is no national or even international guidance about which treatments to use and at what point in the disease. […] Careful research into what causes myositis, working out whether certain types of myositis respond or not to certain treatments, understanding which patients are most at risk of serious complications, and looking at how we can diagnose myositis more accurately is all vitally important, to improve the clinical care of sufferers with myositis. […] A non-funded organisation, UKMYONET, has been created, which aims to share expertise and generate ideas for future studies and drug trials to eventually produce new treatments.

• #79 FRI0337 INCIDENCE AND PREVALENCE OF MYOSITIS ASSESSED BY MULTI-SOURCES CAPTURE-RECAPTURE METHODOLOGY | Annals of the Rheumatic Diseases

  https://ard.bmj.com/content/78/Suppl_2/850.2

  Precise epidemiology of myositis epidemiology remains largely unknown (1). […] To overcome these difficulties we undertook a capture-recapture survey that takes advantage of a multi-sources case ascertainment to estimate the number of cases missed by any one source and to correct the prevalence rate (2). […] This first study based on a multi-sources capture-recapture methodology and ACR/EULAR criteria is very likely to provide an accurate estimation of myositis epidemiology.

• #80 Myositis ( – University of Manchester)

  http://research.bmh.manchester.ac.uk/CIGMR/research/autoimmune/Autoimmunity/Myositis/

  Dr Chinoy is chair of the Euromyositis Registry, an EU-wide web-based consortium created to obtain uniform, longitudinal data of adult and juvenile IIM to achieve increased knowledge on disease course and prognosis of myositis. […] UK MYONET activities and those of the UK JDRG tie in well with ongoing international activities.

• #81 Diagnostic delay of myositis: an integrated systematic review | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-022-02570-9

  The overall pooled mean diagnostic delay for IIM was (27.91 months or 2.25 years, 95% CI 15.0340.79 months, I2=99%) and is similar to other rheumatologic diseases with long diagnostic delay. […] We found longer diagnostic delay in gatekeeper health systems when compared with non-gatekeeper health systems, indicating that the difference in accessibility to specialists influences time to diagnosis. […] There were no differences in diagnostic delay between studies where MSA was tested and those where MSA was not tested. […] The presence of complex clinical characteristics that were found to contribute to diagnostic delay were reported in relation to ASS (n=2), DM (n=2), IBM (n=6), and mixed IIM (n=1). […] We did not identify any qualitative studies examining how people with myositis experienced diagnostic delay. […] These outcomes highlight the critical need to improve awareness, understanding and diagnosis of IIM.

• #82

  https://link.springer.com/article/10.1007/s00415-022-11459-3

  Our study, currently with 1300 recruited sIBM cases, is the largest sIBM cohort to date. […] We expect to identify several sIBM genetic variants and locus that cluster in disease associated genes. […] The identification of associations with genes involved in immune or neurodegenerative pathways using WES and WEG could open a new treatment opportunity. […] Further improvement of current diagnostic criteria and the definition of potential genetic and/or laboratory biomarkers are necessary to improve diagnostic accuracy, reduce diagnostic delay and meet the therapeutic window of opportunity for immunomodulatory drugs at early disease stages.

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